Shock absorber



July 18, 1933.

E. F. RossMAN 1,918,565

SHOCK ABSORBER Filed April 2, 1930 I WAM al1/fin J Fossmdrz a al sorber adapted to control both ing and separating movements tively movable members,

Patented July 18, 1933 UNITED V.STATES PATENT yOFFICE lEDWIN F. ROSSMA, OF DAYTON, OHIO, ASSIGNOR TO DELGO PRODUCTS CORPORATION,

0F DAY-TON, OHIO, A.C0RPORATION' OF DELAWARE sriocx ABsonBnn Application led April 2,

This invention relates to improvements in hydraulic shock absorbers.

It is among the objects of the'present invention to providea hydraulic shockv abthe approachof two relafor instancethe frame and aXle of a vehicle.

A further object of the invention is to pro vide a double acting shock absorber of simple structure and design, capable of beingproduced commerciallyat a minimum expenditure of time and material.`

Further objects and advantages of the present invention will be -apparent from the following description, reference being had to the accompanying drawing wherein apre ferred embodiment of one form of the presen invention is clearly shown.

ln the drawing: Fig. lis a fragmentary side view of the vehicle chassis, a shock absorber embodying the present invention being shown applied thereto.

Fig. 2 is ya longitudinal sectional view take through the Fig. 3 is a shock absorber. v i l detail sectional view taken'along the line 3-3 of Fig.

2, certain parts being omitted for the sake of clearness. i

Fig. 4 is a transverse sectional view taken along the line 4-4 of Fig. 2. Referring to the drawing,

the numeral 2O y designates the frame of the vehicle Whichis r supported upon the only one of which is shown. The shock abaXle 21 by springs 22,

sorber comprises a casing'` 23,'presenting a fluid reservoir 24 and a cylindrical portion 25. The two open ends of the cylindrical portion 25 are closed by the screw plugs 26 and 27, properly gasketed to eliminate leaks.

lithin the cylindrical portion 25 of the casing 23 there is provided a fluid displacement member 28 having a central recess'29 which forms two piston head. portions 3() and 3l tied together by an intermediate web portion The huid displacement member 28 forms a compression chamber atv each end of the cylindrical portion 25, the pist-on head portion 30 33, while the forming the compression chamber piston head portion 3l forms i930. seriai No. 440,952.

the compression chamber 34. The ends of the fluid displacement member are recessed,

terminates short of the ment member.

. is provided a longitudinal. channel 37 which ends of said displace# A duct 38m the fluid displacement member connects the recess of the piston head portion 30 with the channel 37, while a similar duct 36 of the piston head V39 connects the recess portion 3l with said channel 37. This channel 37 as shown in Fig. 4 is so located on the fluid displacement member 28 that it coop wall of the cylindrical closed low pressure pas crates with the inner portion Q5 to form a sage. By closed is meant that this lowpressure passage is not iii communication with the fluid reservoir 24, but only in communication with the compression chambers 33 and 34 through the respective ducts 38 and 39 and recesses 35 and 36.

The inner ends of the recesses 35 and 36 have reduced portions 40 and 4l respectively. Within the recess 35 there is provided an annular ridge 42 eXtendi end of the recess and su portion 4() of said recess.

ng toward the outer roundingthe reduced A similar ridge 43 is provided in the recess 36 surrounding the'smaller portion 4lof said recess. These ridges 42 and 43 form annular valvel seats within said recesses.

In-each recess 35 and valve mechanism adapt of'fluidthrough therespective ducts 38 39. .Inasmuch as the valve mechanisms 36theie is provided a ed to control the flow and for the respective recesses areV alike, only one of them will be described f or the sake of brevity.

The valve mechanisin comprises a ringshaped valve 45 sion 46` which reaches into .eter portion40 of the r having a cylindrical eXtentlie smaller diamecess 35. One end of a coil spring 47- is secured to the ring-shaped valve 45 in anysuitable manner, end of said spring being providedV lar groove 48 adjacent the outer endV the other secured in an annuwithin Athe recess 35 thereof. `This'spring 47 not only yieldably urges the, valve 45 into engagement with the annular valve seat- 42, but it also substantially maintains said valve 45 in propercoaxial alignment with the recess portion whereby the valve may properly engage the valve seatvto shut off the recess 35 from its portion 40.l The valve mechanism also comprises a tubular valve member 50 slidably supported within the ring-shaped valve and its cylindrical eX- tension 46. The longitudinal passage 5l through the valve has a reduced portion 52 providing a fluid restricting'orifice. The tubular valve 50 has la head portion 53 engaging the `inner end ofthe cylindrical eX- tcnsion 46 of the ring-shaped valve 45. A spring 54 has one end engaging the ringshaped valve 45, the other a washer 55 secured at the outer end of the tubular valve 50, said spring urging the tubular valve 50 so that its head pertion'53 is yieldably maintained in engagement with the inner edge of the cylindrical extension 46. A slot 56 is provided in the outer surface of the tubular valve 50 and extends from the inner edge of its head portion 53 a substantial distance beyond the confines of the ring-shaped valve 45 as shown in the Fig. 3.

Duct 38, as has been mentioned, opens into the longitudinal channel 37 lof the fluid displacement member 28. The other end of said duct 38 opens into a channel 60 provided in the piston which in turn is in communication with the recess 29 thereof, said .recess being in communication withthe fluid reservoir 24. In the end of the duct 38 communicating with the channel 60 there is provided a check valve comprising the valve cage 6l and the ball checkvalve 62. This vcheck valveprevents the flow of fluid from the duct 38' intol theliuid reservoir through channel 60. How-v ever check valve 62 will be moved to establish a flow of fluid from the reservoir into the duct 38 tocompensate for any Huid losses in the compression chamber 33 which might obtain through leakage past the piston or in any other manner. y

The casing 23 presents two aligned, but oppositely disposed bearings 65 and 66 in which the rocker shaft 67 of the shock absorber is journalled. One end of this rocker shaft extends outside the casing, a packing gland 68` substantially preventingfluid Yleaks from the inside of the casing alongsaid rock'- er shaft past the bearing 65. The shaft portion 67 extending outside'the casing has the shock absorber operating arm '69 secured thereto, the free end of the arm being swivelly attached to oneend vof the connecting link 70. The opposite end of this connecting link is secured to a Abracket 7l which is clamped to the axle 21 by the member72.

A rocker leVerSO is attached tothe shaft 67 Within the casing'23, said rocker lever carrying a shoe 81 having parallel ends which sion chamber 33 lit into and engage the side walls of the recess 29 in the fluid displacement member 28.

The device operates in the following manner:

When the wheels of the vehicle, not shown, strike an obstruction in the roadway, springs 22 will'be flexed toward the frame 20, resulting in an upward movement of the link 70 and thereby a clockwise rotation of the shock absorber operating arm 69. Rotating the arm 69 clockwise will likewise rotate the shaft 67v clockwise, and thus the rocker arm 80 will be moved toward the left as regards Figs. 2 and 3. The fluid displacement member in being' moved toward the left will cause the fluid within the compression chamber 33 to have pressure exerted thereupon, the initial escape of the fluid from said compresbeing through the orifice 52 and Vpassage 5l into the duct 38 and thence into the channel 37. From this channel the fluid will flow from the duct 39 and thence into the recessed portion 41 against the valve 451%, pushing said valvev from its valve seat 43 against the effect of the spring 47E and thus lestablishing a flow from the duct 39 into thecompression chamber 34.

This initial escape of fiuid from the compression chamber 33 will be restricted by the orifice 52, said restriction to the flow of fluid from the compression chamber 33 resisting the movement of the fluid displacement member toward the lever and consequently resisting the upward or compression movement of the spring 22. If the obstruction met is ofv sufficient size to causeA excessive pressure within the compression chamber 33 which cannot be sufficiently relieved by the flow through the orifice 52, then the excessive pressure acting upon the end of the tubular valve 50 will move said valve 50 to the right relative to the ring-shaped valve 45 in Figs. 2 and 3. This will move the head 53 of the tubular valve 50, away from the edge of the cylindrical extension 46 of the ring-shaped valve, and thereby another restricted flow of fluid will be established from the recess 35 through the slot 56 in valve 50 past the head portion 53 thereof into the duct 38 and thence through channel 37 and duct 39 past the valve 45E into the compression chamber 34. The movement of the valve 50 relative to the valve 45 will be in accordance with the pressure within the compression chamber 33, and consequently the `restrictionto the flow of fluid will be in accordance with the degree of pressure exerted uponthe fluid in said compression chamber. f

-When the spring 22 has reached the limit of its flexure caused by this particular obstruction, the tendency of said spring is suddenly toreturn to normal, unfleXed position with'a rebounding movement which, if per mitted, will result in disagreeable jars andV jolts being transmitted tothe frame of the cach piston recess vehicle. The present device substantiallyV controls the return of the spring towards its relaxed or normal position for, as said@ spring begins to move Vaway fromthe frame 20, the connecting link TO 'Wil rotate the arm T9 counter-clockivice, resulting in a movement of the fluidr c mlziceiiieiit member toward `he right' i ards Figs. 2 and 3. ln this instancevalve B with its orifice 52B and its fluid passage slotl will functionV in a manner substantially similar to the corresponding valve in the opposite end of the fluid 'displacement member. Restriction of the flow of iii l from the compression chamber Se into the duct 39 and channel 37 Will resist the Vreturn movement of the springsfQQ and thus substantially eliminate the rebounding thereof The'ball check valve @2R will function also to replenish the iiui'dpsuply in compression chamber 34 if' for anyreav son an;7 of the fluid'therein has been lost due to leaks or the like. i v f ln this invention applicant provides a. shock absorberhaving two compression.V chambers which, during the operation of the device disch arges 'from one into ie-other 'Without in any Way sending the. fluid into thefiuid reservoir. The valve mechanism at one end of the fluid displacement member operates independently of the valve mechanism atY the opposite end 'of the fluid displacement mem-- ben likewise one valve mechanism maybe adjusted to control its cycle of shock absorber operation Without Vin any Way affecting the valve me hanism which controls another cycle of Ashock absorber operation. In this instance the `Working separate from that of the supply, thereby insuring substantially continuous and efiicient operation.

vVhile the form of ent invention herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow. l Y

What is claimed is as follows:

1. A shock absorber comprising in combination, a casing presenting a cylinder; a piston in said cylinder forming a compression chamber at each end thereof, said piston having a recess in each end thereof, a duct leading from the inner end of each recess to the outer, peripheral surface of the piston and a channel in operating with the Wall of the cylinder'to form a passage connecting the tivo ducts of the two piston recesses; an annular ridge 1n surrounding the mouth of the duct leading thereinto; a disc valve yieldably urged into engagement with said annular ridge, said valve having a central channel; a stem-valve slidably supported in the central channel of the disc valve and having a head portion engaging the side of the disc medium is kept embodiment of the pres-v said surface of the piston co-' valve which engages vthe `annular ridge; a spring yieldably'urging said stem-valve to maintain l"its head portion in engagement 'with the disc-valve; a` slot in the outer surchamber at each end thereof; said piston hav-V ing a recess in each end thereof; a duct leadmg from the inner end of each recess tothe outer, peripheral surface of the piston and a channel 1n said surface of the piston cooperating With the Wall of the cylinder' to formV a passage connecting the two ducts of the two piston recesses; an annular ridge in each piston recess surrounding the mouth of the duct leading theremto; a ring-shaped valve yieldably urged into engagement `With the annular ridge, said valve having a tubular Y portion extending into the respective duct; a

tubular valve member slidably carried bv tho tubularportion of the ring-shaped valve, said tubular valve having a head engaging the end of said tubular portion Within the duct;`a spring yieldably urging the head of the tubular valve into engagement with the ring-shaped valve; a slot in the outer surface ofthe tubular-valve extending from the inner side of the head thereof a substantial distance beyond the outer edge of the ringshaped valve; and means for reciprocatrfr said piston. y b

3: A shock absorber comprising in combination, a casing presenting a cylinder; a piston 1n said cylinder forming a compression chamber at each end thereof, said piston havmg a recess 1n each end thereof, a. duct leading from the inner end of each recess to the.

outer, peripheralsurface of the pistonand a channelin said surface of the piston cooperating With the Wall of the cylinder to form a passage connecting the tivo ducts of the two piston recesses; an annular ridge in each piston recess surrounding the mouth of the cuclt leading thereinto; valvefmechanism in ac 1lpliston recess for controlling the lioW 0f miphgpplgh the respective ducts, each valve I comprising a ring shaped valve; a spring secured at one end to the valveand the other end to the piston, said spring yieldably supporting said valve and urging it into engagement With the annular ridge,

said ring-shaped valve having a cylindrical extension reaching intothe respective duct, a tubularv valve slidably carried Within the cylindrical extension of the ring-shaped valve, said tubular valve having a metering orifice Within itand a head member at Vone,

end engaging the inner end of the cylindrical ing the piston.

.placement member extension ofthering-shaped valve, said tubular valve having also a longitudinal slot in its outer surface extending from the inner edge of its head member substantially beyond the confines. of the outer surface of the ringshaped valve, a spring about the tubular valve secured atone end to the tubular valve, the other end ofV said spring engaging the ring-shaped valve, yieldably urging the head member of the tubular valve into engagement with the cylindrical extension of the ring-shaped valve; and means for reciprocat- ,4. A- double acting shock absorber comprising in combination, a casing presenting a fluid reservoir and a cylinder;'a fluid diswithin the cylinder forming a compressionchamber at each end thereof, said member having a channel in its outer surface terminating short of each end of said member, said channel cooperating with the wall of the cylinder to form a low compression passage between recessesat the respective ends of the member; valve mechanism in each piston recess, each. mechanism comprising two oppositely acting valves for controlling the flow of fluid into and from said low compression passage; check valves in the fluid displacement memberv for establishing a fluid flow from the reservoir into the respective recesses to compensate for Huid losses in the cylinder; vand means for reciprocating` sait fluid displacement mem- 5. A shock absorber comprising in combination, a displacement chamber; a displacement member in said chamber; a fluid res- .ervoir; and valve mechanism for controlling valve; a spring yieldably maintaining the first mentioned valve upon its seat; and an other spring interposed between the said first mentioned valve and the shank of the second valve to urge said second valve upon its seat.

6. A shock absorber comprising in combination, a displacement chamber; a displacement member in said chamber; a fluid vreservoir; and valve mechanism for controlling the flow of fluid between the said chamber and reservoir, said mechanism comprising a port surrounded by a valve-seat; a valve engageable with said valve seat and providing a second valve-seat; a second valve engageable with said second valve seat, said second valve having a tubular shank extending through and slidably supported by the first mentioned valve; a restriction at one end of the tubular shank, providing a constant flow orifice; a springvyieldably maintaining the first'mentioned valve upon its seat; and another spring interposed between the said iirst mentioned valve and the shank of the second valve to urge said second valve upon its seat.

EDWIN F. ROSSMAN. 

